Hydrogenic impurity states in zinc-blende symmetric InGaN/GaN multiple quantum dots

Based on the effective-mass approximation, the ground-state donor binding energy of hydrogenic impurity in a cylindrical zinc-blende (ZB) symmetric InGaN/GaN multiple quantum dots (QDs) is investigated variationally. It is found that the donor binding energy has a maximum value when the impurity is located at the center of the QDs. Numerical results also show that, for the impurity located at the center of the middle QD, the donor binding energy has a minimum value with increase in the middle barrier width. The donor binding energy is insensitive to the increment of the middle barrier width when the middle barrier width is large. Moreover, we find that the donor binding energy is basically invariable with increase in the Indium (In) composition when the impurity is located at the center of the middle barrier. (C) 2010 Elsevier B.V. All rights reserved.